JP2006202610A - Self-luminescent light emitting panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-luminescent light panel causing no functional deterioration even if an environmental temperature changes, and its manufacturing method. <P>SOLUTION: In this self-luminescent panel 10, a self-luminescent element 15 formed by holding at least one or more light emitting functional layers between a pair of electrodes 12, 14 is formed on a substrate 11, a sealing member 16 to isolate the self-luminescent element 15 from the outside air, and the sealing member 16 is pasted to the substrate 11 with an adhesive layer 18 to form a sealed space M covering the self-luminescent element 15. The internal pressure P of the sealed space M in which the self-luminescent element 15 is sealed by the sealing member 16 at t°C satisfies a formula (1). In the formula, P<SB>max</SB>is the maximum outside atmospheric pressure assumed in a use environment, P<SB>min</SB>is the minimum outside atmospheric pressure assumed in the use environment, P<SB>d</SB>is cohesion breaking atmospheric pressure at the maximum preservation temperature, t<SB>max</SB>is the maximum preservation temperature, t<SB>min</SB>: the minimum preservation temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a self-luminous panel and a method for manufacturing the same.

  A self-luminous panel is a self-luminous element having a solid light-emitting layer formed on a substrate. What is a liquid crystal display panel in which a liquid crystal layer is sealed between substrates and a backlight on the back is controlled by this liquid crystal layer? The basic structure is different. That is, the self-luminous panel generally includes a solid light-emitting layer and a sealing space for sealing the solid light-emitting layer, and a portion formed of the solid layer and a gas formed as a sealing space around it are filled. A structural feature is to provide a sealed space.

  The self-luminous panel has such a solid space and a sealed space filled with gas, and does not have a liquid layer. Therefore, the liquid crystal layer (liquid layer) is solidified (freezing) or vaporized (boiling). Compared with a liquid crystal display panel in which the use or storage temperature range is limited by (), the use or storage temperature range can be extended from a low temperature range to a high temperature range. That is, the self-luminous panel can generally be operated or stored at an extremely low temperature or high temperature, and a display panel having higher environmental resistance than a liquid crystal display panel can be obtained.

  An organic EL panel which is one of such self-luminous panels is formed by forming an anode made of a transparent electrode such as ITO on a glass substrate, and forming an organic film including a light-emitting layer made of an organic compound on the glass substrate. An organic EL element on which a cathode made of a metal electrode such as Al is formed is a basic configuration, and the organic EL element is arranged as a unit surface light emitting element on a flat substrate.

  It is known that the characteristics of this organic EL display panel deteriorate when the organic film and the electrode are exposed to the outside air. This is due to the phenomenon that moisture intrudes into the interface between the organic film and the electrode, thereby preventing the injection of electrons, generating a dark spot as a non-light emitting region or corroding the electrode. In order to improve stability and durability, a sealing technique for blocking the organic EL element from the outside air is indispensable. Various proposals have been made regarding this sealing technique. As an effective means in terms of productivity and durability, a sealing method for covering the electrode and the organic film on a glass substrate on which the electrode and the organic film are formed is provided. A method of adhering the stop member is employed.

  The process of adhering the sealing member according to this conventional technique on the glass substrate will be described with reference to FIGS. In order to bond the sealing member 4 to the glass substrate 1 that has completed the electrode and organic film forming steps, the entire circumference of the organic EL layer 3 is placed on the glass substrate 1 or the bonding surface of the sealing member 4. The adhesive layer 2 is formed so as to surround it. Fig.1 (a) has shown the state which formed the adhesive bond layer 2 in the sealing member 4 side. The adhesive layer 2 is made of an ultraviolet curable or thermosetting resin such as an epoxy resin, and is applied onto the sealing member 4 by a dispenser.

Then, as shown in FIG. 1 (b), after the glass substrate 1 moves to the O _{2 +} N ₂ gas atmosphere sealed device 5, bonding the sealing member 4 and the glass substrate 1, the sealing device The internal pressure of the sealing member 4 is increased to eliminate the difference between the pressure generated in the sealing member 4, and then the epoxy resin is cured by irradiating ultraviolet rays to bond the periphery of the sealing member 4 and the glass substrate 1. Yes.

  Here, in the formation of the adhesive layer 2 using the above-mentioned dispenser, the application height of the adhesive layer 2 cannot be accurately regulated. It is necessary to set it as high as 200 μm. When the sealing member 4 is pressed against the adhesive layer having such a height and bonded, the height of the adhesive layer 2 is crushed to about 1/10, and the adhesive layer 2 is sealed. Since the entire circumference of the stop region is surrounded, the internal pressure of the sealing member rises when the adhesive layer 2 is crushed, and the inside of the sealing space becomes a positive pressure state of 1.2 atm or higher. Since this pressure difference is caused by the application height of the resin forming the adhesive layer 2, the pressure generated due to the variation in the application height also varies, and the pressure in the sealing device 5 is adjusted. However, it causes a sealing failure after the sealing process, and it is difficult to say that it is in an appropriate state.

  Therefore, in Patent Document 1 below, the adhesive layer 2 that surrounds the entire periphery of the organic EL layer 3 is formed by screen printing that can form a thin adhesive layer with a high system, and the adhesive layer under atmospheric pressure. It is proposed that the glass substrate 1 and the sealing member 4 are bonded via 2. Accordingly, when the sealing member 4 is bonded onto the glass substrate 1, the pressing displacement of the adhesive layer is reduced, and an excessive positive pressure is not generated in the sealing space even when the operation is performed under atmospheric pressure. It becomes possible to avoid subsequent sealing failure. By setting the printing height of the adhesive layer by screen printing to 20 to 100 μm, the pressure in the sealed space can be suppressed to less than 1.2 atmospheres.

JP 2002-329552 A

  However, even if the sealing operation is performed under atmospheric pressure and the pressure in the sealed space is close to atmospheric pressure immediately after the sealing member is bonded, the internal pressure in the sealed space varies depending on the temperature change. It will be. As described above, the use or storage temperature range of the self-luminous panel is one advantage compared to the liquid crystal display panel. However, taking advantage of this advantage, the self-luminous panel is self-luminous in extremely low or high temperature environments. When the panel is placed, the following problems occur due to pressure fluctuations in the sealed space caused by temperature changes.

  That is, for example, when the self-luminous panel is exposed to an environmental temperature of −40 ° C. (generally the lowest storage temperature of the organic EL panel) for a long time, the temperature in the sealed space also decreases to −40 ° C. There is. At this time, when the internal pressure of the sealed space sealed at normal temperature (for example, 25 ° C.) and atmospheric pressure (1.0 atm) is −40 ° C., P = 1.0 according to Boyle-Charles' law. X (273-40) / (273 + 25) = 0.882 atm. When the outside air pressure is 1.0 atm, the sealed space becomes a negative pressure of 0.218 atm. When the external air pressure is as high as 1.050 hPa (1.050 / 1.013 = 1.037 atm), the negative pressure is further increased to 0.265 atm.

  If the sealing space of the organic EL panel becomes negative pressure, it easily deforms when an external force is applied to the sealing member or the like, and the drying member or the like attached to the inner surface of the sealing member comes into contact with the organic EL layer. There arises a problem that the functional deterioration of the organic EL layer occurs.

  When the self-luminous panel is exposed to a high environmental temperature for a long time, the temperature in the sealed space also becomes high, the gas in the sealed space expands, and the internal pressure changes to a positive pressure ( For example, when the internal pressure of the sealed space sealed at 25 ° C. and 2.0 atm is 100 ° C., P = 2.0 × (273 + 100) / (273 + 25) = 2.503 atm, and the external pressure is 1 In the case of 0.0 atm, the positive pressure is 1.566 atm). When the positive pressure in the sealing space exceeds the cohesive failure pressure of the adhesive used for sealing, there is a problem that the sealing is broken and the function of the self-luminous panel is deteriorated.

  This invention makes it an example of a subject to cope with such a problem. That is, it is an object of the present invention to provide a self-luminous panel with high environmental resistance by providing a self-luminous panel that does not deteriorate in function even when the ambient temperature changes and a method for manufacturing the same.

  In order to achieve such an object, the self-luminous panel and the manufacturing method thereof according to the present invention include at least the configurations according to the following independent claims.

  [Claim 1] A self-light-emitting element in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from outside air. When the temperature in the sealed space where the self-luminous element is sealed by the sealing member is the lowest storage temperature of the self-luminous element, the internal pressure of the sealed space is the self-luminous A self-luminous panel characterized in that an internal pressure of the sealing space at the time of sealing is set so as to be larger than an external atmospheric pressure of a panel use environment.

  [Claim 2] A self-light-emitting element in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member for blocking the self-light-emitting element from the outside air is provided. When the temperature in the sealed space where the self-luminous element is sealed by the sealing member is the maximum storage temperature of the self-luminous element, the internal pressure of the sealed space and the self-luminous The internal pressure of the sealing space at the time of sealing is set so that the pressure difference in the usage environment of the panel is smaller than the cohesive failure pressure of the adhesive that bonds the sealing member at the maximum storage temperature. Self-luminous panel.

  [Claim 3] A self-light-emitting element in which a self-light-emitting element formed by sandwiching at least one light-emitting functional layer between a pair of electrodes is formed on a substrate, and a sealing member for blocking the self-light-emitting element from outside air is provided. A self-luminous panel, wherein the internal pressure P of a sealed space in which the self-luminous element is sealed by the sealing member at a temperature t ° C. satisfies the following formula (1).

但し、
Ｐ_ｍａｘ：使用環境で想定される最大外気圧、
Ｐ_ｍｉｎ：使用環境で想定される最小外気圧、
Ｐｄ：保存最高温度における接着剤の凝集破壊気圧、
ｔ_ｍａｘ：保存最高温度（℃）、
ｔ_ｍｉｎ：保存最低温度（℃）

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C)

  [5] A self-light-emitting element in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member for blocking the self-light-emitting element from outside air is provided. In the panel manufacturing method, when the temperature in the sealed space where the self-luminous element is sealed by the sealing member is the lowest storage temperature of the self-luminous element, the internal pressure of the sealed space is A method of manufacturing a self-luminous panel, wherein an internal pressure of the sealing space at the time of sealing is set so as to be larger than an external pressure of an environment in which the self-luminous panel is used.

  [Claim 6] A self-light-emitting element in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from outside air. In the method for manufacturing a panel, when the temperature in the sealed space where the self-luminous element is sealed by the sealing member becomes the maximum storage temperature of the self-luminous element, the internal pressure of the sealed space and The internal pressure of the sealing space at the time of sealing was set so that the atmospheric pressure difference in the usage environment of the self-luminous panel was smaller than the cohesive failure pressure of the adhesive that bonds the sealing member at the maximum storage temperature. A method of manufacturing a self-luminous panel characterized by

  [Claim 7] A self-light-emitting element in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from the outside air A method for manufacturing a self-luminous panel, comprising: a sealing step of sealing in an environment of Pf and t satisfying the following formula (2).

但し、
Ｐ_ｍａｘ：使用環境で想定される最大外気圧、
Ｐ_ｍｉｎ：使用環境で想定される最小外気圧、
Ｐｄ：保存最高温度における接着剤の凝集破壊気圧、
Ｐｆ：封止時の気圧、
ｔ_ｍａｘ：保存最高温度（℃）、
ｔ_ｍｉｎ：保存最低温度（℃）、
ｒ：接着剤の押圧による増圧係数（ｒ＝Ｐ／Ｐｆ）

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
Pf: Pressure at the time of sealing,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C.),
r: coefficient of pressure increase due to pressing of adhesive (r = P / Pf)

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is an explanatory view showing the structure of the self-luminous panel according to the embodiment of the present invention. The self-light-emitting panel 10 has a self-light-emitting element 15 formed by sandwiching at least one light-emitting functional layer 13 between a pair of electrodes 12 and 14 on a substrate 11 and blocks the self-light-emitting element 15 from the outside air. A sealing member 16 is provided. The sealing member 16 is affixed on the substrate 11 via an adhesive layer 18 so as to form a sealing space M that covers the self-luminous element 15. The organic EL panel is taken as an example of the self-luminous panel 10 to describe its configuration example. A substrate 11 is formed of a glass substrate, and a first electrode 12 made of ITO is formed on the glass substrate. A light-emitting functional layer 13 made of an organic light-emitting material layer (organic layer) is formed, and a second electrode 14 made of a metal electrode is formed thereon to form an organic EL element (self-light-emitting element 15). .

A glass sealing substrate is used as the sealing member 16, and a drying member 17 is attached to the inner surface that is recessed in a concave shape in order to form the sealing space M. The drying member 17 is provided to absorb and remove the initial moisture present therein and the moisture released or infiltrated with time after the sealing member 16 is bonded. In particular, since the organic layer forming the organic EL element is vulnerable to heat and cannot remove moisture by heat treatment before sealing, such initial moisture cannot be completely eliminated. Therefore, in the panel using the current organic EL material, such a drying member 17 is generally disposed in the sealing member. The sealed space M is filled with a gas (for example, a mixed gas of nitrogen (N ₂ ) and oxygen (O ₂ )) that does not adversely affect the self-light-emitting element 15 at the time of sealing.

In the self light emitting panel 10 according to the embodiment of the present invention, first, the temperature in the sealed space M where the self light emitting element 15 is sealed by the sealing member 16 is the lowest storage temperature of the self light emitting element 15. When (t _min ) is reached, the internal pressure of the sealing space M at the time of sealing is set so that the internal pressure of the sealing space M becomes larger than the external pressure of the environment in which the light-emitting panel 10 is used.

Here, the minimum storage temperature (t _min ) is the minimum storage temperature at which the light-emitting element 15 can function normally. Unless it is stored at a temperature lower than the minimum storage temperature, the self-luminous emission is obtained. Element 15 will function normally. Taking an organic EL element as an example, it is generally said that the minimum storage temperature is about −40 ° C. Even if stored at such an extremely low temperature, if the storage minimum temperature is exceeded, problems occur in the organic EL element. There is no.

  That is, since the temperature in the sealing device at the time of sealing is generally room temperature (about 25 ° C.), the temperature in the sealing space M decreases from about 25 ° C. to about −40 ° C. after sealing, and this temperature Even when the pressure in the sealing space M is reduced due to the pressure change accompanying the change, the sealing is performed so that the internal pressure in the sealing space M becomes larger than the external pressure of the environment in which the light-emitting panel 10 is used. Since the internal pressure of the sealing space M at the time is set, if the storage space M is stored at a temperature higher than the minimum storage temperature, the sealing space M does not become negative pressure, and the sealing space M becomes negative pressure. Problems such as panel dents can be avoided.

Further, as another feature of the self-luminous panel 10 according to the embodiment of the present invention, when the temperature in the sealing space M reaches the maximum storage temperature of the self-luminous element 15, the internal pressure of the sealing space M is as follows. The sealing space M at the time of sealing is such that the pressure difference between the usage environment of the light-emitting panel 10 and the self-luminous panel 10 is smaller than the cohesive failure pressure of the adhesive that bonds the sealing member 16 at the maximum storage temperature (t _max ). The internal pressure is set.

Here, the maximum storage temperature (t _max ) is the maximum storage temperature at which the light-emitting element 15 can function normally. Unless it is stored at a temperature higher than the maximum storage temperature, the self-light-emitting element 15 is self-luminous. Element 15 will function normally. Taking an organic EL element as an example, it is generally said that the maximum storage temperature is about 100 ° C. Even if stored at such a high temperature, there is no problem with the organic EL element as long as it is below this maximum storage temperature. .

  That is, since the temperature in the sealing device at the time of sealing is generally room temperature (about 25 ° C.), the temperature in the sealing space M rises from about 25 ° C. to 100 ° C. after the sealing, and this temperature change occurs. Even when the pressure in the sealed space rises due to the accompanying pressure change, the pressure difference between the internal pressure in the sealed space M and the use environment of the self-luminous panel 10 bonds the sealing member 16 at the maximum storage temperature. Since the internal pressure of the sealing space M at the time of sealing is set so as to be smaller than the cohesive failure pressure of the adhesive to be bonded, the adhesive layer 18 breaks and seals if stored at the maximum storage temperature or lower. There is no problem that the stop is broken.

  The cohesive failure pressure of the adhesive at this time is also described in the adhesive specifications, but actually varies greatly depending on the material and shape of the sealing member 16. Therefore, this value should be obtained experimentally and set with a sufficient statistical margin.

  Further, as another feature of the self light emitting panel 10 according to the embodiment of the present invention, the internal pressure P of the sealing space M in which the self light emitting element 15 is sealed by the sealing member 16 at a temperature t ° C. is expressed by the following formula ( It is characterized by satisfying 1).

但し、
Ｐ_ｍａｘ：使用環境で想定される最大外気圧、
Ｐ_ｍｉｎ：使用環境で想定される最小外気圧、
Ｐｄ：保存最高温度における接着剤の凝集破壊気圧、
ｔ_ｍａｘ：保存最高温度（℃）、
ｔ_ｍｉｎ：保存最低温度（℃）

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C)

Here, the maximum external atmospheric pressure (P _max ) assumed in the use environment can be normally set to about 1.050 hPa (1.050 / 1.013 = 1.037 atm). Further, the minimum external air pressure assumed in the use environment can be generally set to about 0.950 hPa (0.950 / 1.013 = 0.938 atmospheres). However, this minimum external air pressure may be even smaller in highlands. As described above, the cohesive failure pressure of the adhesive at the maximum storage temperature is obtained experimentally and should be set with a statistically sufficient margin.

According to this embodiment, when the internal pressure P of the sealing space M in which the self-luminous element 15 is sealed by the sealing member 16 at the temperature t ° C. satisfies the formula (1), the sealed space M after sealing. The internal pressure of the sealed space M does not become negative with respect to the external air pressure of the use environment even if the temperature of t _nim to t _max changes. The pressure difference from the atmospheric pressure does not exceed the cohesive failure pressure of the adhesive. Therefore, problems such as dents in the self-luminous panel 10 and problems such as sealing breakage do not occur.

  Hereinafter, a method for manufacturing the self-luminous panel 10 according to the embodiment of the present invention will be described.

  In the method for manufacturing the self-light-emitting panel 10, a self-light-emitting element 15 formed by sandwiching at least one light-emitting functional layer 13 between a pair of electrodes 12 and 15 is formed on a substrate 11. Each process for providing the sealing member 16 which shields from is included. Taking an organic EL panel as an example, as shown in FIG. 3, an element forming step S <b> 1 </ b> A for forming an organic EL element (self-luminous element 15) on a substrate 11 and a drying member for attaching a drying member 17 to the inner surface of the sealing member 16. The attachment step S1B is performed in parallel, a sealing step S2 is performed in which the substrate 11 and the sealing member 16 are bonded together via the adhesive layer 18, and then an inspection step S3 or the like is performed as necessary.

Here, in the method for manufacturing the self-luminous panel 10 according to the embodiment of the present invention, when setting the internal pressure of the sealing space M in the sealing step S2, as described above, the self-light-emitting panel 10 is self-luminous by the sealing member 16. When the temperature in the sealing space M in which the element 15 is sealed becomes the minimum storage temperature (t _min ) of the self-light-emitting element 15, the internal pressure of the sealing space M is the external pressure of the environment in which the self-light-emitting panel 10 is used. The internal pressure is set so as to be larger. For example, when the temperature in the sealed space M in which the light emitting element 15 is sealed by the sealing member 16 reaches the maximum storage temperature (t _max ) of the light emitting element 15, the sealed space M The internal pressure is set so that the pressure difference between the internal pressure of the self-luminous panel 10 and the use environment of the self-luminous panel 10 is smaller than the cohesive failure pressure (Pd) of the adhesive that bonds the sealing member 16 at the maximum storage temperature (t _max ). The

  According to such an internal pressure setting, as described above, the temperature in the sealing space M decreases from the normal temperature at the time of sealing to the lowest storage temperature after sealing, and the sealing space M is changed by the pressure change accompanying this temperature change. Even if the internal pressure drops, the sealed space M does not become negative as long as it is stored above the minimum storage temperature, and the dent of the panel caused by the negative pressure in the sealed space M Etc. can be avoided. Further, even when the temperature in the sealed space M rises from the normal temperature at the time of sealing to the maximum storage temperature after sealing, and the pressure in the sealed space increases due to the pressure change accompanying this temperature change, As long as it is stored at the maximum storage temperature or lower, there is no problem that the adhesive layer 18 is broken and the sealing is broken.

Then, the actual sealing step is performed by the sealing device 5 as shown in FIG. 1B, and the environment setting of the pressure Pt and the temperature t in the sealing step is performed by the temperature and pressure in the sealing device 5. Is made. In the sealing device 5, a desired gas that does not adversely affect the self-luminous element 15 (preferably at least one or more types of combustion-supporting gas, for example, nitrogen (N ₂ ) and oxygen (O ₂ as a combustion-supporting gas). )). Here, in the manufacturing method of the self-luminous panel 10 according to one embodiment of the present invention, the sealing step is performed in an environment in which the pressure Pf and the temperature t satisfying the following formula (2) are set.

但し、
Ｐ_ｍａｘ：使用環境で想定される最大外気圧、
Ｐ_ｍｉｎ：使用環境で想定される最小外気圧、
Ｐｄ：保存最高温度における接着剤の凝集破壊気圧、
Ｐｆ：封止時の気圧、
ｔ_ｍａｘ：保存最高温度（℃）、
ｔ_ｍｉｎ：保存最低温度（℃）、
ｒ：接着剤の押圧による増圧係数（ｒ＝Ｐ／Ｐｆ）

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
Pf: Pressure at the time of sealing,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C.),
r: coefficient of pressure increase due to pressing of adhesive (r = P / Pf)

  Here, r is a coefficient (pressure increase coefficient) indicating an increase in internal pressure in the sealing space M caused by pressing the adhesive layer 18 when the substrate 11 and the sealing member 16 are bonded, and r = It is a value set by P / Pf (P: internal pressure immediately after sealing, Pf: environmental pressure at the time of sealing). When there is a variation in the height of the adhesive layer 18 before bonding and it is necessary to increase the pressing width, r increases. Generally, r is set in the range of 1.1 to 1.2.

Even if the temperature of the sealed space M after sealing changes from t _nim to t _max by performing the sealing process in an environment of such pressure Pf and temperature t, the internal pressure of the sealed space M is used. There is no negative pressure relative to the external atmospheric pressure, and the pressure difference between the internal pressure of the sealed space M and the external pressure of the use environment does not exceed the cohesive failure pressure of the adhesive. Therefore, problems such as dents in the self-luminous panel 10 and problems such as sealing breakage do not occur.

  More specifically, a sealing step is performed in which the median value in the range of Pf is set as a set value. According to this, it is possible to cope with a wide range of temperature changes when storing in an environment in which changes in the storage temperature are equally shifted to the high temperature side and the low temperature side.

  In one embodiment of the present invention, the sealing step includes the step of forming an adhesive layer 18 that surrounds the entire circumference of the light emitting functional layer 13 by screen printing, and the adhesive layer 18 under Pf / r atmospheric pressure. The process of bonding the board | substrate 11 and the sealing member 16 through this is included. According to this, since the height of the adhesive layer 18 can be made uniform by screen printing, the value of r described above can be reduced, and the internal pressure in the sealing space close to the set Pf is set. It is possible to set the internal pressure accurately.

  Applying specific numerical values, an example of setting the environmental pressure Pf in the sealing process in the above-described embodiment is shown as follows.

[Setting Example 1] P _max : 1.037 atm, P _min : 0.938 atm, Pd: 1.0 atm, t _max : 100 ° C, tmin: -40 ° C, t: 25 ° C, r: 1.10 1.205 <Pf <1.407 (atmospheric pressure) and 1.326 <P <1.548 (atmospheric pressure). More specifically, taking the median value of Pf, the set pressure in the sealing device 5 is set to 1.306 atm.

[Setting Example 2] When the sealing process is performed at high altitude, P _min may be 0.8 atm. In this case, if the other conditions are the same as in setting example 1, the setting pressure in the sealing layer value 5 is 1.205 <Pf <1.308 (atmospheric pressure), and the internal pressure in the sealing space at that time is 1.326 <P <1.438.

  Below, the specific example regarding the structural member of embodiment mentioned above is shown, and it is set as the Example of this invention.

  [Organic EL element] A specific structure and material examples of an organic EL element (self-emitting element 15) in which a first electrode 12, an organic layer (light emitting functional layer 13), and a second electrode 14 are laminated on a substrate 11 are shown. It is as follows.

(A) substrate;
The substrate 11 is preferably a flat plate or film having transparency, and glass or plastic can be used as the material.

(B) an electrode;
When assuming a method of taking out light from the substrate 11 side (bottom emission method), the first electrode 12 is an anode made of a transparent electrode, and the second electrode 14 is a cathode made of a metal electrode. As an anode material to be applied, ITO, ZnO or the like can be used and formed by a film formation method such as vapor deposition or sputtering. As the cathode, metal having a low work function, metal oxide, metal fluoride, alloy, etc., specifically, a single layer structure such as Al, In, Mg, etc., and a laminated structure such as LiO ₂ / Al are used for vapor deposition. The film can be formed by a film forming method such as sputtering.

(C) an organic layer;
When the first electrode 12 is an anode and the second electrode 14 is a cathode, the organic layer (light emitting functional layer 13) is generally a layered structure of a hole transport layer / light emitting layer / electron transport layer, The light emitting layer, the hole transport layer, and the electron transport layer may be provided by laminating not only one layer but also a plurality of layers, and either of the hole transport layer and the electron transport layer may be omitted. The layer may be omitted and only the light emitting layer may be used. Moreover, as an organic layer, organic functional layers, such as a hole injection layer, an electron injection layer, a hole barrier layer, and an electron barrier layer, can be inserted according to a use.

  The material of the organic layer can be appropriately selected according to the use of the organic EL element. Examples are shown below, but are not limited thereto.

  The hole transport layer only needs to have a function of high hole mobility, and any material can be selected and used from conventionally known compounds. Specific examples include porphyrin compounds such as copper phthalocyanine, aromatic tertiary amines such as 4,4′-bis [N- (1-naphthyl) -N-phenylamino] -biphenyl (NPB), 4- (di- Organic materials such as stilbene compounds such as p-tolylamino) -4 ′-[4- (di-p-tolylamino) styryl] stilbenzene, triazole derivatives and styrylamine compounds are used. In addition, a polymer-dispersed material in which a low-molecular organic material for hole transport is dispersed in a polymer such as polycarbonate can also be used.

A known light emitting material can be used for the light emitting layer. Specific examples include aromatic dimethylidin compounds such as 4,4′-bis (2,2′-diphenylvinyl) -biphenyl (DPVBi), 1,4- Styrylbenzene compounds such as bis (2-methylstyryl) benzene, triazole derivatives such as 3- (4-biphenyl) -4-phenyl-5-t-butylphenyl-1,2,4-triazole (TAZ), anthraquinone derivatives , Fluorescent organic materials such as fluorenone derivatives, fluorescent organic metal compounds such as (8-hydroxyquinolinato) aluminum complex (Alq ₃ ), polyparaphenylene vinylene (PPV), polyfluorene, polyvinylcarbazole (PVK) The phosphorescence from triplet excitons such as platinum complexes and iridium complexes can be used for light emission. The organic material (special table 2001-520450) can be used. It may be composed only of the light emitting material as described above, or may contain a hole transport material, an electron transport material, an additive (donor, acceptor, etc.) or a light emitting dopant. These may be dispersed in a polymer material or an inorganic material.

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer, and any material can be selected from conventionally known compounds. Specific examples include organic materials such as nitro-substituted fluorenone derivatives and anthraquinodimethane derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, and the like.

  The hole transport layer, the light emitting layer, and the electron transport layer are applied by a wet process such as a coating method such as a spin coating method and a dipping method, a printing method such as an inkjet method and a screen printing method, or a vapor deposition method and a laser transfer method. The dry process can be used.

  [Sealing member] The material of the sealing member 16 is not particularly limited, but is preferably made of glass or metal.

  [Adhesive] The adhesive used for the adhesive layer 18 is an adhesive such as a thermosetting type, a chemical curing type (two-component mixing), a light (ultraviolet) curing type, and an acrylic resin, an epoxy resin, Polyester, polyolefin and the like can be used. In particular, it is preferable to use an ultraviolet curable epoxy resin. A suitable amount of spacers (preferably glass or plastic spacers) having a particle diameter of 1 to 100 μm is mixed (about 0.1 to 0.5% by weight) with such an adhesive and applied using a dispenser or the like.

  [Drying member] As a desiccant for forming the drying member 17, for example, a molded article containing a hygroscopic agent and a resin component may be laminated on a release sheet or may be used alone. .

The hygroscopic agent is not particularly limited as long as it has a function capable of adsorbing at least water, but is preferably a compound that chemically adsorbs water and maintains a solid state even when moisture is absorbed. Examples of such compounds include metal oxides, metal inorganic acid salts and organic acid salts, and it is particularly preferable to use at least one of alkaline earth metal oxides and sulfates. Examples of the alkaline earth metal oxide include calcium oxide (CaO), barium oxide (BaO), magnesium oxide (MgO), and the like. Examples of the sulfate include lithium sulfate (Li ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), calcium sulfate (CaSO ₄ ), magnesium sulfate (MgSO ₄ ), cobalt sulfate (CoSO ₄ ), and gallium sulfate (Ga ₂ ). (SO ₄ ) ₃ ), titanium sulfate (Ti (SO ₄ ) ₂ ), nickel sulfate (NiSO ₄ ), and the like. In addition, an organic material having a hygroscopic property can be used as the hygroscopic agent.

On the other hand, the resin component is not particularly limited as long as it does not interfere with the moisture removing action of the hygroscopic agent, and is preferably a material having a high gas permeability (that is, a material having a low barrier property, particularly a gas permeable resin). ) Can be used. Examples of such materials include polymer materials such as polyolefin, polyacryl, polyacrylonitrile, polyamide, polyester, epoxy, and polycarbonate. Of these, polyolefin-based ones are preferred in the present invention. Specific examples include polyethylene, polypropylene, polybutadiene, polyisoprene, and copolymers thereof.
The content of the hygroscopic agent and the resin component may be set as appropriate according to these types and the like. Usually, the total amount of the hygroscopic agent and the resin component is 100% by weight, and the hygroscopic agent is about 30 to 85% by weight and the resin component 70. It may be about ˜15% by weight. Preferably, the hygroscopic agent is about 40 to 80% by weight and the resin component is 60 to 20% by weight, and most preferably the hygroscopic agent is about 50 to 70% by weight and the resin component is 50 to 30% by weight.

  The hygroscopic molded body can be obtained by uniformly mixing these components and molding them into a desired shape. In this case, it is preferable to mix the moisture absorbent, the gas adsorbent and the like after sufficiently drying them in advance. Further, when mixing with the resin component, it may be heated to a molten state as necessary.

[Various types of organic EL panels] The organic EL element (self-emitting element 15) may form a single organic EL element or may have a desired pattern structure and constitute a plurality of pixels. You may do.

  In the latter case, the display method may be single-color light emission or multi-color light emission of two or more colors. In particular, in order to realize a multi-color light emission organic EL panel, three types of light emission functions corresponding to RGB are used. A method of forming a light emitting functional layer of two or more colors including a method of forming a layer (coloring method), a method of combining a color conversion layer using a color filter or a fluorescent material with a monochromatic light emitting functional layer such as white or blue (CF Method, CCM method), a method that realizes multiple light emission by irradiating electromagnetic wave to the light emitting area of the monochromatic light emitting functional layer (photo bleaching method), low molecular organic materials of different luminescent colors are formed on different films in advance. It can be performed by a laser transfer system in which a film is transferred onto a single substrate by laser thermal transfer. Further, the driving method of the organic EL element may be either a passive driving method or an active driving method.

  According to the self-luminous panel and the manufacturing method thereof according to the embodiment or the example of the present invention described above, it is possible to provide the self-luminous panel and the manufacturing method thereof that do not cause functional deterioration even when the environmental temperature changes. A self-luminous panel with high environmental resistance can be obtained.

It is explanatory drawing of a prior art. It is explanatory drawing which shows the self-light emission panel which concerns on embodiment of this invention. It is explanatory drawing explaining the manufacturing method of the self-light-emitting panel which concerns on embodiment of this invention.

Explanation of symbols

10 Self-luminous panel 11 Substrate 12, 14 Electrode (first electrode, second electrode)
13 Light-Emitting Functional Layer 15 Self-Emitting Element (Organic EL Element)
16 Sealing substrate 17 Drying member 18 Adhesive layer

Claims (10)

A self-light-emitting panel in which a self-light-emitting element formed by sandwiching at least one light-emitting functional layer between a pair of electrodes is formed on a substrate, and a sealing member for shielding the self-light-emitting element from the outside air is provided,
When the temperature in the sealed space where the self-luminous element is sealed by the sealing member becomes the minimum storage temperature of the self-luminous element, the internal pressure of the sealed space is the usage environment of the self-luminous panel. A self-luminous panel, wherein an internal pressure of the sealing space at the time of sealing is set so as to be larger than an external pressure. A self-light-emitting panel in which a self-light-emitting element formed by sandwiching at least one light-emitting functional layer between a pair of electrodes is formed on a substrate, and a sealing member for shielding the self-light-emitting element from the outside air is provided,
When the temperature in the sealed space where the self-luminous element is sealed by the sealing member reaches the maximum storage temperature of the self-luminous element, the internal pressure of the sealed space and the usage environment of the self-luminous panel The self-luminous panel, wherein the internal pressure of the sealing space at the time of sealing is set so that the pressure difference becomes smaller than the cohesive failure pressure of the adhesive that bonds the sealing member at the maximum storage temperature. A self-light-emitting panel in which a self-light-emitting element formed by sandwiching at least one light-emitting functional layer between a pair of electrodes is formed on a substrate, and a sealing member for shielding the self-light-emitting element from the outside air is provided,
A self-luminous panel, wherein an internal pressure P of a sealed space in which the self-luminous element is sealed by the sealing member at a temperature t ° C satisfies the following formula (1).

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C) The self-luminous panel according to claim 1, wherein the sealed space is filled with nitrogen (N ₂ ) and oxygen (O ₂ ). A method of manufacturing a self-light-emitting panel in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from outside air. There,
When the temperature in the sealed space where the self-luminous element is sealed by the sealing member becomes the minimum storage temperature of the self-luminous element, the internal pressure of the sealed space is the usage environment of the self-luminous panel. A method for manufacturing a self-luminous panel, wherein an internal pressure of the sealing space at the time of sealing is set so as to be larger than an external pressure. A method of manufacturing a self-light-emitting panel in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from outside air. There,
When the temperature in the sealed space where the self-luminous element is sealed by the sealing member reaches the maximum storage temperature of the self-luminous element, the internal pressure of the sealed space and the usage environment of the self-luminous panel A self-luminous panel characterized in that the internal pressure of the sealing space at the time of sealing is set so that the pressure difference is smaller than the cohesive failure pressure of the adhesive that bonds the sealing member at the maximum storage temperature. Production method. A method of manufacturing a self-light-emitting panel in which a self-light-emitting element having at least one light-emitting functional layer sandwiched between a pair of electrodes is formed on a substrate, and a sealing member is provided to block the self-light-emitting element from outside air. There,
The manufacturing method of the self-light-emitting panel characterized by having the sealing process which seals in the environment of Pf and t which satisfy | fills following formula (2).

However,
P _max : Maximum external pressure assumed in the usage environment,
P _min : Minimum external pressure assumed in the usage environment,
Pd: cohesive failure pressure of the adhesive at the maximum storage temperature,
Pf: Pressure at the time of sealing,
t _max : Maximum storage temperature (° C.),
t _min : Minimum storage temperature (° C.),
r: coefficient of pressure increase due to pressing of adhesive (r = P / Pf)   The method for manufacturing a self-luminous panel according to claim 7, wherein a sealing step is performed with a median value in the range of Pf as a set value.   The method for manufacturing a self-luminous panel according to any one of claims 5 to 8, wherein the sealed space is filled with at least one kind of combustion-supporting gas.   The sealing step includes a step of forming an adhesive layer that surrounds the entire circumference of the light emitting functional layer by screen printing, and bonding the substrate and the sealing member through the adhesive layer under Pf / r atmospheric pressure. The manufacturing method of the self-luminous panel described in any one of Claims 7-9 characterized by including the process of performing.

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